The object of the present invention is to maintain a hot fluid temperature at a desired location in a fluid supply system.
It is desirable to maintain the temperature of hot water at a faucet without any substantial modifications to a traditional plumbing system. Traditional plumbing systems are deficient in maintaining hot water temperatures at a faucet or other plumbing fixture, such as a showerhead. Typically, a person who desires to use hot water opens a valve, such as a faucet or shower control valve, and allows water to flow. Initially, the water is not hot, but rather cold or warm. After a period of time the water becomes hot and is used. This approach not only costs the user time, it also wastes a substantial amount of water because the water flows down a drain while the water temperature slowly rises to the desired temperature.
The problem described arises not only in hot water supply systems, but in any hot fluid supply system using piping to deliver hot and cold fluid from a source to a discharge valve. The temperature of the fluid within a hot fluid supply pipe of a hot fluid supply system decreases to an ambient temperature over time when the fluid is not flowing. As a result, when hot fluid is desired, the user needs to allow the fluid to flow until the temperature at the discharge valve reaches the desired temperature.
Two methods are commonly used to maintain the temperature of water at a discharge valve. Both methods involve recirculating hot water from the hot water side of a hot water supply system back to a source, such as a hot water heater. One method involves routing a pipe from the hot water supply pipe at the furthest fixture within a plumbing system back to the water heater which supplies the hot water to the plumbing system. The installation of such a return line has a substantial cost. Typically, it involves the routing of many feet of piping throughout a house.
A second method involves installing a pump in proximity to a discharge valve between the hot water supply pipe and the cold water supply pipe connected to that discharge valve. This will control water temperature near the fixture by shunting water from the hot water supply pipe to the cold water supply pipe. Often the pump is electrically powered and may be controlled by timing controls, temperature controls or a manual switch which cause the pump to operate at desired times or at desired water temperatures. Such a pump may also be used to enhance the performance of a hot water supply system employing the return line method described above. The pump is installed within the return line to cause the water to be returned to the hot water source.
Several problems are associated with using water pumps. The water pump has a significant cost. The water pump requires electrical power, at a cost, to operate and install. The water pump has a tendency to malfunction and require repairs over time. The water pump emits undesirable noise. Since the water pump is electrically operated within the proximity of water it presents a potential electrical shock safety hazard.
Attempts to address these problems can be found within the following patents: U.S. Pat. Nos. 5,323,803, 5,622,203 and 5,819,785.
There is a need for a simple mechanical fluidic device which will control and maintain fluid temperature at or near a discharge valve. In particular, there is a need for such a device which will control and maintain water temperature at or near a discharge valve. The device should be able to be manufactured at a low cost. It should not emit noise. It should not require electrical power for operation. The maintained and controlled temperature should be manually adjustable from a position outside of the fluid. There is also a need for an adjustable temperature controlled faucet and a temperature controlled hot water supply system having these features.
The present invention satisfies these needs.